Big baby at 38 weeks - gest diabetes this late?

[biggest]

I always thought GDD comes on earlier in pregnancy but at a scan today at 38 weeks, baby is measuring big (make that BIG!). Nearly 9 lbs already and size has shot off scale since last scan a month ago.
I have to have a glucose test next week, but urine and bloods from a couple of weeks ago were all normal.
Is it possible to get sudden and late onset of GDD at this stage?
I am so annoyed as was only being monitored closely by an over cautious consultant because of problems in first pregnancy. Can't help thinking they were looking for something to justify all the monitoring - she was almost gleeful at the size of baby's podgy tum!

Yes, it is possible - my experience almost exactly mirrors yours. I turned out to be a little insulin resistant, which means I was never actually diabetic, but my blood sugar was swinging about a bit. May have been fine but I had some oral steroids for asthma which pushed me over the edge at 36 weeks. They made me follow the diabetic diet and blood testing regime which was tbh hell on earth because I didn't have time to find out about it all properly and so just starved myself till planned induction at 38 weeks.

At least it's not for long (as everyone kept saying to me though it's little compensation when you're right in the middle of it all)

Just checked and blood sugar levels have been constant throughout pregnancy up until 36 weeks at last check. I do have family history though, brother and dad have Type 1 and Type 2.
I KNEW I shouldn't have written my 'water birth' birth plan last night, talk about tempting fate!
Did you have a big baby?

well 38 weeks is term really and 'almost 9 lbs' isn't actually that big really!

plus-i wouldn't rely entirely on the scans. mine said i was growing jonah lomu's lovechild and ds was actually only 8 13!

It's probably nothing to worry about (in any case scans are only accurate to about 2lbs either way!) but if you're worried, ask for a test if you can get one as GDD can be dangerous for the baby.

there's question marks over whether I developed GDD late in my 2nd PG (test at 28wks was clear) - my DS was 11lb 14oz. he had jaundice and low blood sugar. birth was fine though

Scans aren't necessarily accurate in late pregnancy - my last one with DD said she was going to be well over 10lbs, but in fact she was just over 9lbs.

And big babies don't necessarily mean gestational diabetes, even with family history. I have strong family history of type II, I put on a lot of weight in pregnancy, and had two 9lb+ babies, so was put through all the horrible full glucose tests a couple of days after birth with both of them, and was absolutely normal. Don't panic. You might have GD, but most likely not.

Ok will try to be calm. Had f'ing hideous first time birth and feeling anxious enough about this one. Was a whisker away from just asking for a caesarean this morning as it all seems so inevitable....
Bollocks

I agree that scans not always accurate, i was told DD1 was big and she was only 7lb 13. However my 3rd and 4th were biggish 9lb 2 and 10lb both born around 38 weeks and they were much easier to deliver. So there might be a bright side. A nice quick labour?!! Have they said when or if they might want to intervene? DS2 was induced as he was 'over 9lb' on scan at 38 weeks/. His measurements were off the scale. you'd think the scale might be able to encompass babies over 9lbs these days!
Good Luck, i bet your labour wont be anywhere near as awful as last time. 2nd babies rarely are. Let us know how you get on and when you bouncing bubba arrives

i should also add that i had added complication of raised BP which was also a factor in inducing my 'big' baby!